In this context, the issue of sensor and actuator location or selection becomes critical. Having an efficient and parsimonious control setup motivates the emergence of all the following methods. In their multi-step heuristic approach to closed-loop flow control design, [1]} propose to rely on the correlation between observed relevant phenomena and sensor signal to choose observations and on clues provided by POD mode decomposition of the flow instabilities to choose actuators location. [2]} and [3]} also leverage POD analyses to derive optimised sensor placement.
